what is the api in config file

"api": {
        "enabled": true,
        "blacklist": [],
        "ip": "0.0.0.0",
        "port": 3680,
        "whitelist": []
    },

public function editApiUser($guid, $username, $password) {
        $admins = $this->mod->getAdmins();
        if (!isset($admins['guid'])) {
            return false;
        }
        $admins[$guid]['api']['username'] = $username;
        $admins[$guid]['api']['password'] = hash('sha512', $password);
        $this->mod->setAdmins($admins);
        return true;
    }